Primaluna - Rolling pre tubes question...



I'm new to rolling tubes, and have been using the stock 12AU7.
I've a PL Prologue premium integrated with 2 12AU7's per channel. I want to test a new pair(before investing in more), so wondering if front or rear position would best reveal the new tubes character?

Thanks,
Darren
128x128dmhenley
Hi David256 if you look at many products that use tube sockets they are mounted onto PCB's, and it's not uncommon to have that same PCB have the power transformer attached to it. PrimaLuna tube sockets are mounted on to heavy-gauge fully ventilated standoffs. The chassis is so heavy I don't think there's a lot of microphony going on.

It's so easy to demonstrate. You can whack the hell out of the chassis and hardly a peep will show up anywhere on any PrimaLuna component. Compare that tube a number of preamps where you simply flip a switch and it rings through the speakers.

I do like composite sockets too. We used some killer ones when we built the Ah! Tjoeb CD player that were da bomb. But the ones we use never fail (well, maybe one) so that's what we're shooting for.

On the microphony question, I've found that tubes can lose a little air and harden up with dampers SOMETIMES. Every case is different. Some microphony CAN be good, evidenced by the sound degrading if it's removed. Is it a distortion artifact? Maybe. But that's one of the charming aspects of tubes. If distortion were the end-all be-all buy an Aragon. They are electrically perfect.

If the tube is already low in microphony, and the circuit isn't a silly one (like this idiocy of 27dB of gain in a preamp), and the socket isn't mounted to a PCB, why bother. It should be done on a case by case basis. What ever sounds best. They cost nothing so why not.
Hello,

I have a PL Dialogue Premium preamp and I am looking to buy a few tubes.  Just want to be clear so that I don't waste my money.  I only need to replace 2 or 4 of the 6 12au7s?  Please advise!  Thank you.
The 2 front tubes are all you need to replace. They have the most affect on the sound. 
If I can get away with only switching out 2 tubes (1 pair) then I can really splurge!  Just to be clear, this is for a preamp.  Thank you.
Oh my bad I overlooked the fact it was a preamp only. I've been so focused on my integrated so I am not sure. Have you Googled or searched Audiogon in the meantime?